The interseeding is the technique where the sowing of the winter crop is placed intercalate in furrows, allowing sowing of the summer crop (soybean) before the harvest of the winter crop such as wheat, corn, sunflower or another similar crop.
In addition, the interseeding facilitates the implementation of the double crop in the region, since summer crop is sowing in dates near the sowings of the first crop.
This improving technique raises an intermediate alternative between covered sowing and the conventional sowing, because it uses machineries to incorporate the seeds in superficial form or very superficial over the implanted pasture or natural field. The chemical factors are modified-by fertilizer, biologically—via seeds and inoculants—and physically in partial form. As far as the implantation, the interseeding is less risky and can be implanted more quickly than the covering sowings.
The wheat is sown in a diagram of two lines and a calculated space to be able to sow soybean or corn between the furrows before harvesting the soybean.
With this methodology the surface of the ground is maintained and covered most of the year, diminishing most of the hydric erosion in lands with slope. In addition it is necessary to obtain a suitable control of the weeds during the crop.
This one improvement technique is recommended in different situations such as:    a. In zones whose relief allows the use of some types of machinery.    b. In grounds that do not allow conventional farming because its edafe limitations.    c. When it is desired to prolong the life of a cultivated pasture.    d. When pretending to increase the total production of the forage incorporating species of better quality and more resistant to diseases.    e. If it is necessary to improve the nitrogen fixation, incorporating leguminous with selected rizobios.    f. If a good vegetable cover does not exist, to protect the seed from environmental factors—temperature, humidity, etc.—in the implantation.    g. When the amounts of perennial weeds or summer species prevent or reduce the winter grass production.    h. After a drought, fire or overgrazing.    i. When the species losses take place by physical problems of the ground-compaction If the situation is extreme, it would be necessary to use renovated chisels—fine tubes and small blocks or a disc dredge.
The interseeding is not advisable in some cases:    a. In escarped zones with slopes that limit the use of machinery. In this case it is convenient to think about using sowing with an aerial cover.    b. In grounds with great drainage problems.    c. If the surface is very uneven, it is more convenient to use a double superficial disc.    d. If a mixed diagram is found—agricultural-cattle, to evaluate very carefully the economic benefit of the interseeding: it can result in more income-production to incorporate the field to the agricultural cycle.
Advantages                speeds the works because it requires little personal and Horse Power.        maintains the vegetal cover, diminishing the loss of humidity.        protects the ground erosion.        optimizes the implantation moment.        pasture can be anticipated because of the firm floor.        reduces costs.State of the Technique and Elements to ConsiderTools        
There are several alternatives that have being presented; in the last years an interseeding that simplifies the tasks (by the different incorporations allowed) have been imported and developed at a national level, in addition to improving the implantation system.
A good interseeding machine is one that:    a. carries out a good bed of sowing.    b. sows accurately and with a good control of dose and depth.    c. does not damage the grain.    d. fertilizes in located form.
Also the accumulated experiences in the use of total herbicides or desiccants, allows diminishing the competition of the platform to improve; giving greater security to the first stage of the process of the interseedings.
We will classify the above according to the amount of used implements and intensity of removal of the ground.
1. Direct sowing                With minimum removal: interseeding machine with discs.        
2. Interseeding                With partial or total removal in the band:        Integral work        Interseeding machine to block in U form or inverted T.        Interseeding machine to rotors        Separated tasks        Disc dray with drawer        Sowing machine+covered fertilizing machine        scarifier chisel (superficial 3 cm)        seeding drawer+covered fertilizing machine        
3. Reduced farming                With total removal:        Chisel+disc dray+sowing machine+fertilizing machine        Double disc dray+sowing machine+fertilizing machine        
1. Direct Sowing
Disk interseeding machine: (Agrometal John Deere, Truax, Bertini, etc.)
Works over the platform opening a furrow that has the width of the disc. It is not our intention to make a description of the different models; only the general characteristics will be mentioned.
There are chassis that support 2 drawers for seeds and fertilizers (in some cases they have 2 drawers of seeds for grass and leguminous) that ends at a double disc set where 2 unloading tubes have being leaned.
The majority of the brand names incorporate the seeds and fertilizers in the same band with the limitations or risks that it causes.
Others with different devices (inclined or straight discs) apply the fertilizers underneath or to the flank and underneath the furrow of the sow.
All come with cutting discs in front of the double discs, with different drawings to facilitate the entrance of the sow organs; there are even brand names that allow annexing indented discs in front of the cutters to open the stubble, facilitating the sowing.
In general, these sowing machines have more weight than the conventional ones, assuring their penetration with 3 springs that press against the ground and can be used or not, according to the stubble.
According to the situation, it will be possible to recommend annexing the sowing machine to a chain dray or worn out teeth.
I. Interseeding Machine to Rotors
Makes the integral work and has all the necessary accessories to make a good sow.
The difference with the previous one is in the replacement of the double discs by a package of rotors that remove the ground in a width of 5 cm and up to 10 cm of depth. In main lines we affirmed that the sowing bed that prepares this type of interseeding is superior to the previous ones, but it has another type of disadvantage that moves it away from optimal working (See Table No. 1).
TABLE 1Differences of the interseedings machineRotorDiscs1.Removes a lot of ground.It has more dependency of2.Has less dependency ofthe pre-sowing herbicide.herbicide because itIt has more initialremoves the vegetation incompetition.the furrow.Minimum growing of annual3.Has less initialweeds.competition.Minor loss of old plants.4.Produces greater growingMinor dependency of post-of annual weeds.sowing herbicides.5.Greater loss of oldWork can be started withplants.more superficial6.Greater dependency ofhumidity, but when thispost sowing herbicides.one is reduced it is7.Must begin working laternecessary to finishby the superficialbefore.humidity but it canMore speed of advance;continue working when theless HP to work.humidity is reduced.Minimum maintenance cost.8.Less advance speed andGreater work width.more HP to work.9.Greater maintenance cost.10.Smaller work width.II. Interseeding Machine to Block (Grassland)
It works over the platform opening a furrow of 5 cm width and 3 cm depth. It consists of a frame with 7 to 9 chisels to 30 cm between each other provided with a block of a triangle form and a hydrostatic depth-control gear. The machine completes with 2 drawers, one for fertilizers and another for seeds.
It is not advisable to sow mixtures of grass and leguminous. In Argentina this method was only used to incorporate the leguminous, although some implanted scallions. The perennial forages failed in great proportion.
This type of interseeding machine has some problems with respect to the previous:                The compaction made by block in the furrow diminishes the initial rooting.        By the type of open furrow less light enters, making the initial growth slower.        It has little work width and greater distance between furrows.        When there are strong rains, the furrow fills with water with the consequences that this brings. Nevertheless, in dry periods it conserves more humidity.        It must have greater certainty in the control of the advance speed because when diminishing it the earth bread does not overturn and falls on the removed furrow covering the seed.III. Interseeding Machine of Block-Seedmatic (Atchinson) New Zelandia        
It differs from the Grassland in:
It has vibratory arcs that join the rudders, doing the work more tediously than the conventional block.
1. The blocks Baker, (inverted T form) leave a fine furrow in surface and enlarged in the base conserving more of the humidity than the Grassland or any one of those of disc or rotors. Allows working more time and expanding the sow time. In addition, avoids the incorporation of straw to the furrow, which prevents the contact of the seed with the ground, limiting the germination.
2. It has a greater amount of sowing furrows (2.50-3 mts width of work with rudders to 15 cm), depositing the fertilizer underneath of the seed and this one is mixed with a sowing bed looser than the sowing machine that makes furrow in a “V” or “U” shape.
3. In case of strong rains, by the type of block, less water enters in the furrow and in addition diminishes the damage that can produce the direct hit of the drops of rain.
4. It has a kit of cutting discs facilitating the work of the land block with residues or gramona.
5. It has a feeder with a sponge that allows sowing any type of seed without breaking it, without affecting the vibration, and of easy cleaning.
IV. Interseeding with Disc Dray
It is made by heavy disc dray without lock, marking the furrow with its weight.
The depth of the work must be of 2 cm and the width of the furrow is in intimate relation with the thickness of the disc. It is very important that the unloading tube of the seeds has a length that allows taking the greater amount of sufficient seeds to the base of the disc, but not so long that it can be mixed with the soil and be covered.
Due to this, there will be a percentage of seeds that will be distributed in the hedge without covering. If to this we added the lack of regulation in the depth and its greater untidiness is essential to increase the density of sowing.
It is possible to think that this system of implantation will better adapt to the annual leguminous (less alfalfa) and annual grasses.
For the work to be more efficient it has to be coupled to the disc dray, a press roller and/or teeth dray, or in their defect, to draze with high loads (10 head/ha) during 1 to 3 days. It is always recommended to fertilize 10 to 15 days before sowing.
V. Interseeding with Scarifier Chisels
Just as the previous, only the implementation is modified and is called scarifier because the chisels work in surface over the horizon.
3. Reduced Farming
Here all the factors are modified: chemicals (fertilizers), biological (seeds or inoculants) and physicals (ground, aeration, porosity, etc).
In this farming, the superficial vegetation is removed with different implements without reversing the soil plan to later make a conventional sowing.
It is advisable:    a. When a superficial ground exists and the reversing of the soil plan is pernicious.    b. When there is excessive ground compaction, limiting the oxygenation, absorption of nutrients, etc.    c. It is desired to take advantage of the accumulated fertilizer (5 cm).    d. When the prairie was thinning by attack of white worm.
At the present time, crops are made respecting the times and harvests, one after another, although there have been several attempts to invent reforms that allow to advance a sowing without having harvested the previous crop. Until now they have been impractical and generally used in a single crop, for example wheat and soybean.
The soybean has the critical period at moments, very different from the one from wheat, corn and sunflower. The interseeding of crops can be a useful tool, although we did not find jobs of interseeding that are based on separating the critical periods of the crops and the structures of sowing, as the specialists said.
The tractor wheels in a traditional interseeding with soybean, step on rows of wheat, corn, sunflower or similar crops and therefore, it is generally not sowing.
There exists, in state of the art techniques, diverse machines/systems for the interseeding of crops, published in patent documents that deserve to be mentioned by their importance, which we can mention:
The publication of application AR 040671 A1, discloses a automotive interseeding machine that allows to sow soybean in wheat crops before its harvest, having the particularity of being self-propelled, and having a sowing train, with great clears and narrow wheels, allows, unlike the traditional interseeding, to sow all the rows of preceding wheat without diminishing the potential yield.
The disadvantage of this machine is that it has operative limitations of labor work as much in the width as in the height, for example, the distances between furrows are 52 cm, and the sowed wheat to 26 cm and when the wheat is not sowed correctly, like when the distances are inferior to 26 cm, in some or all the lines, when sowing the soybean some of the wheels of the sowing machine step on the wheat, in addition when the crop (wheat, corn, sunflower, and others) is in the developed state to more than 1 meter of height, diminishes the yield potential because this machine deteriorates the crop previously sowed.
The publication of the Argentinean Patent AR 201,522, discloses an interseeding machine that includes a frame, having a plurality of blades carrier arms and link to at least some of the remaining cross-sectional members a plurality of sowing blocks, being the lifting cross-sectional members of these blocks after the last lifting cross-sectional member of these arms with the cutting blades; being each one of these arms and these blocks, in its respective cross-sectional members, link to it by individual subjection means the height regulation of the held element; having at the same time each cross-sectional member a plurality of this subjection means to itself and regularly spaced, so that the subjection means of a posterior cross-sectional member are located in half of the distance between two consecutive subjection means of previous cross-sectional member, being then the linking means of each cross-sectional member alternated aligned inwardly according to the advance direction of the machine; being the mentioned unloading tubes of the deposits disposed immediately behind each seeding block.
The publication of Argentinean Patent No. AR 000149B1, discloses an interseeding machine of drag, particularly an implantation machine of valuable forages species and difficult to seed and preferred destined to carry out the sowing-interseeding, in indistinct form, in implanted crops to improve such or directly in natural pasture to enrich them with certain species, the machine is of the type that includes a chassis with the hydraulic lifting and it is characterized for having a dispenser for the seeds, constituted by at least a pair of cross-sectional aligned hoppers with its three internal systems of removal of seeding material and by the fixed hoppers that externally, together with the corresponding chassis supports, conform the protection means of the distribution of the seeds and the respective rotating hoppers.
The disadvantage of these previous machines is that they have operative work labor limitations in the width between the furrows and as well as the height, and occupying 100% of the crop ground, with displacement direction in the free spaces between the lines of the crops in developed state, preferably to more than 1 meter, allowing to make the work under the direct and regular sowing method with a system of distances change between the furrows according to the working crop with the purpose of intercalating the summer crop, as for example, soybean between the lines of wheat, corn, sunflower or of similar winter crop, obtaining the crop implantation in times superposed of different crops.